The U.S. Pat. No. 5,409,436 discloses an adjustable grip device comprising a pressure block compressing one end of a compression spring, so as to control the pressure range of the compression spring. As a result, the resistance of the grip device is adjusted. When the adjustment is made to have a greater resistance, the spring is under the pressure of the pressure block for a prolonged period of time, thereby resulting in the fatigue of the spring. The efficiency of the grip device is thus reduced.
The distance between the two handles of the conventional grip device is too great for the palm of a woman or child. A normal man will feel uncomfortable if the distance between the handles is smaller.